A strap assembly for sporting footwear, and in particular, adjustably positionable strap assemblies.
In boots and other footwear for sporting activities, such as boots for skiing or snowboarding, inline skates, ice skates, and the like, a plurality of means for securing the user""s foot in the boot are frequently provided. For example, it is common to provide both a lacing system for closing the forward opening in the boot upper, as well as one or more straps extending generally around the user""s foot and/or ankle. In a typical arrangement, a two-part strap assembly attaches to either side of the boot heel portion, with a clasp or some other attachment mechanism that allows the straps to be adjustably connected with the straps disposed generally around the forward portion of the user""s foot.
Such straps provide several advantages over boots having only a lacing system to secure the boot about the user""s foot. Laces provide a convenient and familiar way for the user to tighten the boot to provide a comfortably fit and a relatively uniform tension along the length of the laces. Straps, on the other hand, are generally much more sturdily constructed than laces, and are designed to exert and withstand much larger axial forces. Straps therefore provide a tighter and more reliable coupling between the user""s foot and the boot, and are less likely to break during use than are laces. Moreover, in boots having both straps and laces, the straps will take the large transient loads that may be generated during use, protecting the laces from being over-stressed and potentially broken.
Another advantage to the sturdier straps is that they allow the user to more tightly secure their foot within the boot. This is particularly important in sporting applications, because the tighter coupling provides the user with greater control. For example, in snowboarding the user controls the glide path down a snowy slope utilizing foot movements to rotate the board about its various axes. Accurate control of the snowboard requires that the user""s feet be very securely retained in the boot, with minimal relative motion between the user""s foot and the boot. In fact, sporting boots will often include a mechanism such as a ratchet to the clasp connecting the straps that provides leverage facilitate tightening of the straps.
A typical structure for a snowboard boot for use with step-in bindings includes an internal high back structure, including a rigid heel cup extending about the user""s ankle with an ankle support disposed above the heel cup and flexibly or pivotally secured to the heel cup. Flexible diagonal connectors may be provided to couple the ankle support to the boot sole. In some sporting footwear an external heel cup may alternatively be provided.
The most common strap assembly for sporting footwear utilizes two straps, each connected on opposite sides of the boot in the heel region, the straps extending around the forward portion of the upper near the base of the user""s ankle. A mechanism is provided, for example, a clasp and ladder strap arrangement, that permits the user to connect and tighten the two straps to each other, thereby pulling the user""s foot securely into the heel cup. In some configurations the straps are connected relatively high on the heel portion of the boot, so that when the strap is tightened the forces in the straps are directed essentially backwards, generally parallel to the sole of the boot. In other configurations the straps are connected lower on the heel portion of the boot, so that when the strap is tightened a component of the forces exerted by the straps is directed downwardly, towards the sole of the boot.
The precise location of the connection between the straps and the boot is important to many users in the various sports utilizing such footwear, for several reasons. The location of the connection will effect the comfort of the boot to the user, and users may have differing preferences for the location of this strap connection. More importantly, the location of the strap connection will impact the flexibility of the ankle portion of the boot and, in particular, the connection between the ankle portion and the heel of the boot. A strap connection disposed higher on the boot will more closely couple rotation of the user""s ankle to the boot heel position than will a lower strap connection. In certain activities, a user may prefer to have the strap connection high on the heel portion of the boot in some instances, and lower in other instances, for the same pair of boots. In snowboarding, for example, a less-flexible ankle portion may be preferred for technically challenging or high-speed runs, and a more flexible ankle portion may be preferred for performing tricks and acrobatic maneuvers. In these cases the user is forced to choose between acquiring multiple pairs of boots for each activity or utilizing a less-than-ideal boot for one or more applications.
The present invention is directed to a multiple position strap assembly for sporting footwear such as snowboard boots, ski boots, skates and the like, wherein position of the strap connection to the boot can be adjusted.
In an embodiment of the present invention, an adjustable strap assembly includes a first strap having a proximal end that is pivotally attached to the boot heel portion on one side, a second strap having a proximal end and that is pivotally attached to the boot heel portion on the opposite side, and a clasp mechanism for adjustably connecting the first strap to the second strap. A slider assembly is used to pivotally attach the straps to the boot heel portion, the slider assembly including a slider plate with an elongate channel having a slot therethrough and a nut plate slidably entrapped in the elongate channel. A screw extends through an aperture in the strap, and engages the nut plate to adjustably and pivotally attach the strap to the boot. The slider assembly allows the user to adjust the position of the straps, and thereby the direction of the forces that are applied by the straps.
In an embodiment of the present invention the elongate slot extends from a relatively high and rearward position on the heel to a relatively low and forward position on the heel.
In an embodiment of the present invention the elongate slot through the medial portion comprises alternating wider and narrower portions that are sized such that the engaged screw and nut plate can be slid between adjacent wider portions of the slot.